US3876879A - Method and apparatus for determining surface characteristics incorporating a scanning electron microscope - Google Patents

Method and apparatus for determining surface characteristics incorporating a scanning electron microscope Download PDF

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US3876879A
US3876879A US414568A US41456873A US3876879A US 3876879 A US3876879 A US 3876879A US 414568 A US414568 A US 414568A US 41456873 A US41456873 A US 41456873A US 3876879 A US3876879 A US 3876879A
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electrons
blocking
detector
detection means
area
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Hiramie T Mcadams
Edward A Gasiecki
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Calspan Corp
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Calspan Corp
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Priority to GB47837/74A priority patent/GB1485449A/en
Priority to DE2452826A priority patent/DE2452826B2/en
Priority to JP12948074A priority patent/JPS5511204B2/ja
Priority to FR7437083A priority patent/FR2250977A1/fr
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
    • G01N23/22—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material
    • G01N23/225—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material using electron or ion
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B15/00—Measuring arrangements characterised by the use of electromagnetic waves or particle radiation, e.g. by the use of microwaves, X-rays, gamma rays or electrons
    • G01B15/04—Measuring arrangements characterised by the use of electromagnetic waves or particle radiation, e.g. by the use of microwaves, X-rays, gamma rays or electrons for measuring contours or curvatures
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B15/00—Measuring arrangements characterised by the use of electromagnetic waves or particle radiation, e.g. by the use of microwaves, X-rays, gamma rays or electrons
    • G01B15/08—Measuring arrangements characterised by the use of electromagnetic waves or particle radiation, e.g. by the use of microwaves, X-rays, gamma rays or electrons for measuring roughness or irregularity of surfaces
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/26—Electron or ion microscopes; Electron or ion diffraction tubes
    • H01J37/28—Electron or ion microscopes; Electron or ion diffraction tubes with scanning beams

Definitions

  • the present invention relates to the analysis of surface characteristics and, more particularly, to a method and apparatus for accurately determining the topography or relative elevations of points on surfaces.
  • the contacting type of device for measuring surface finishes or profiles usually comprises the sensing of surface elevations by a stylus in contact with the surface to be measured.
  • the disadvantages of this type of apparatus are the resolution limitations imposed by the radius of the stylus tip and the need to employ extremely light contacting pressures to prevent damage to the surface being measured.
  • the noncontacting devices usually consist of optical apparatus such as optical-microscopes. These devices, although capable of detecting the profile of an object in a plane perpendicular to the optical axis, are not suited for quickly and accurately determining the complete three dimensional topography or contours of the surface of such object. Moreover when the dimensions of the elevation increments are smaller than the wavelength of light, optical measuring devices are incapable of detecting the same.
  • the profile or contours of the edge of an object can be detected by placing such edge perpendicular to the axis of the irradiating beam. If it were possible to slice the object into many segments and look at the profile of the edges of each segment, then enough data could be obtained to define the complete topography or surface contours of the object. It is the purpose of the present invention to provide a method and apparatus whereby such data can be obtained without the necessity of contacting or destroying the object as would result if the object were slicedvinto a large number of sections.
  • the present invention provides means providing an impinging beam of electrons on a surface, the topography of which is to be determined, detection means for detecting electrons emanating from the surface in response to said impinging beam, means providing relative motion between said impinging beam and the surface such that said impinging beam impinges upon various points on the surface producing at each point electrons emanating therefrom and shield means for preventing said emanating electrons from a portion of the points on the surface from reaching said detection means, whereby the output of said detection means is a function of the elevation of said portion of points.
  • FIG. 1 is a schematic representation of the apparatus according to the present invention.
  • FIG. 2 is an enlarged pictorial fragmentary view of a portion of the apparatus illustrated in FIG. 1;
  • FIG. 3 is a sectionalview taken along line 3-3 of FIG. 2;
  • FIG. 4 is a view similar to FIG. 3 illustrating a different angular arrangement of the elements.
  • a housing 10 defines an evacuated chamber 12 through which projects the electronoptical column 14 of a conventional scanning electron microscope, the deflection apparatus of which causes a narrow beam of electrons 16 to scan a specimen 18 under investigation.
  • the specimen I8 is supported on a suitable platform or stage 20 which can be moved, among other desired degrees of freedom, linearly in the direction of arrow A by a suitable actuator such as motor 22.
  • a detector 24 is responsive to the electron beam 26 emitted or emanating fromthe specimen 18 in response to the impinging beam 16 which sweeps lines in the direction of arrow A and indexes in the direction of arrow B. Alternatively lines can be swept in the direction of arrow B. It is significant that only those electrons emitted from specimen 18 which travel linearly or in straight lines be detected.
  • detector 24 preferably comprises a backscattered electron collec- I tor or an unbiased secondary emission collector. Moreover the electron sensitive area of this detector should be as small as possible and preferably approaching a point.
  • a shield means 28 suitably adjustably supported by housing 10 and adjustably movable with respect to specimen 18, said shield means terminating in an edge 30 at the operative end thereof.
  • the electron-optical column is under the control of a scan generator 32 which synchronizes the motion of the electron beam with a display and/or recorder 34 which responds to a suitably amplified signal from detector 24 via line 36.
  • the display can comprise a cathode ray tube as is well known.
  • the surface of specimen 18 may have an irregular cross-sectional contour or profile of peaks and valleys which contour may be different in different plane's.
  • the profile is illustrated as grooves having equal peaks and valleys, the difference in elevations of which, the apparatus of the present invention functions to efficiently and accurately detect.
  • the electron sensitive area of detector 24 is depicted by point D.
  • a plane L containing this point and edge 30 makes a known angle with the plane M forming the surface of platform 20.
  • Plane L intersects the specimen surface in a plurality of points P P ,'P P,, the elevations of whichare to be determined with respect to a datum plane M or, equivalently, with respect to a plane parallel thereto and containing edge 30.
  • a line in the plane L originating in a point P in the specimen surface and terminating at the detector D is intersected by the edge 30 at a point R.
  • the distance from point P to point R is a function of the elevation X of the point P relative to the plane which contains edge 30 and is parallel to the plane said distance fixing a distance S measured in the direction of the arrow A. Electrons emanating in straight lines from areas of the specimen surface containing points such'as P to the right of point P as viewed in FIG. 3 and below plane L will be blocked from reaching the sensitivearea D of the detector and, therefore, will be incapable of generating an output signal therefrom to display 34.
  • X S tan 6 where: Xis.the elevation of a point P on the surface, as measured from. the plane which contains edge 30 and is parallel-to plane M. i S is-the distance in the direction of arrow A from pointR to a planecontaining edge 30 and perpendicular to plane M.
  • the surface can be moved or indexed relative to the edge 30 and the detector 18 permitting'the .determination of the boundaries of additional surfaces areas. This can be repeated as desired to determine the complete topography or elevations of all points on the surface.
  • the-support 20 and shield means 28 have been depicted in parallel planes substantially perpendicular to the axis of the electronoptical column wherein 0 is an acute angle less than 90 other angular arrangements are contemplated. In fact, it has been determined that a preferred orientation would be where 0 equals 90. To this end, the support and shield means could be suitably rotated with respect to the axis of the electron optical column, as depicted schematically in FIG. 4. In this case the elevation X is given by:
  • B is the angle between the axis of the electron optical column and the plane containing the shield means edge and the sensitive area of the detector.
  • shield means 28 has been disclosed as a planar element having a fine edge
  • other forms are contemplated such as a positive field which blocks electrons from impinging on the detector by the capture thereof. This field, however, must not influence electrons which are in the sight of the detector.
  • a method of enabling the determination of surface elevation comprising the steps of:
  • Apparatus for enabling the determination of surface elevation with respect to a datum plane comprismg: i
  • d. means for locating the boundary of said first area by detecting the location of points on the surface at which the output of said detection means abruptly changes in value whereby the relative elevations of said points can be determined.
  • said blocking means comprises a shield spaced from the surface and located between the surface and said detection means.
  • said means for projecting a beam of electrons includes means for causing said beam to scan the surface.
  • a display device for displaying the output of said detection means.
  • g. means for synchronizing the display device with said scanning electron beam.
  • said means for projecting a beam of electrons includes means for causing said beam to scan the surface.
  • a display device for displaying the output of said detection means
  • an electron sensitive portion of said detection means having an area approaching that of a point, and wherein the boundary of the first area is a line on the surface which is defined by the intersection of the surface by a plane containing said extremity and said electron sensitive portion.
  • g. means for blocking electrons from additional areas of the surface from falling on said electron sensitive portion.

Abstract

Method and apparatus for determining surface characteristics such as elevations of points on a surface wherein; an electron beam scans the surface causing electrons to be emitted from the surface; an electron sensitive detector develops signals in response to the emitted electrons impinging thereupon; a shield is located above the surface for blocking electrons emitted from an area of the surface from reaching the detector, the boundary of the area comprising a line that is a function of the elevation or contour of points on the surface, which line is sensed by the detector as a locus of points on the surface wherein the output of the detector abruptly changes in value.

Description

United States Patent [1 1 McAdams et al.
METHOD AND APPARATUS FOR DETERMINING SURFACE CHARACTERISTICS INCORPORATING A SCANNING ELECTRON MICROSCOPE Inventors: I-Iiramie T. McAdams, Williamsville; Edward A. Gasiecki, Depew, both of NY.
Assignee: Calspan Corporation, Buffalo, NY.
Filed: Nov. 9, 1973 Appl. No.: 414,568
US. Cl 250/307; 250/310 Int. Cl H0lj 37/26; GOln 23/04 Field of Search 250/306, 307. 309, 310.
References Cited UNITED STATES PATENTS l2/l970 Norton 250/3l0 ELECTRON-OPTICAL COLUMN AXIS 1 Apr. 8, 1975 3.597.607 8/l97l Campbell 250/310 Primary E.ramine r.lames W. Lawrence Assistanl Examiner-C. E. Church Attorney, Agent, or Firm-wAllen .I. .laffe 57 ABSTRACT Method and apparatus for determining surface characteristics such as elevations of points on a surface wherein; an electron beam scans the surface causing electrons to be emitted from the surface; an electron 26 Claims l Drawing Figures PATENTEUAFR 88375 3,876,879 sum 2 n; 2
AXIS OF ELECTRON- OPTICAL 0 ELECTRON-OPTICAL COLUMN Axls A.
FIG.3
1 METHOD AND APPARATUS FOR DETERMINING SURFACE CHARACTERISTICS INCORPORATING A SCANNING ELECTRON MICROSCOPE BACKGROUND OF THE INVENTION The present invention relates to the analysis of surface characteristics and, more particularly, to a method and apparatus for accurately determining the topography or relative elevations of points on surfaces.
There are presently known methods and structures for measuring and analyzing the surface profiles of various objects. These can generally'be classified into two categories, namely, the contacting types and the noncontacting types. I
The contacting type of device for measuring surface finishes or profiles usually comprises the sensing of surface elevations by a stylus in contact with the surface to be measured. The disadvantages of this type of apparatus are the resolution limitations imposed by the radius of the stylus tip and the need to employ extremely light contacting pressures to prevent damage to the surface being measured.
The noncontacting devices usually consist of optical apparatus such as optical-microscopes. These devices, although capable of detecting the profile of an object in a plane perpendicular to the optical axis, are not suited for quickly and accurately determining the complete three dimensional topography or contours of the surface of such object. Moreover when the dimensions of the elevation increments are smaller than the wavelength of light, optical measuring devices are incapable of detecting the same.
SUMMARY OF THE INVENTION The'foregoing disadvantages, as well as others, are overcome according to the teachings of the present invention which provides an improved method and apparatus for measuring the complete surface topography of objects.
Generally, with either an optical microscope or an electron microscope the profile or contours of the edge of an object can be detected by placing such edge perpendicular to the axis of the irradiating beam. If it were possible to slice the object into many segments and look at the profile of the edges of each segment, then enough data could be obtained to define the complete topography or surface contours of the object. It is the purpose of the present invention to provide a method and apparatus whereby such data can be obtained without the necessity of contacting or destroying the object as would result if the object were slicedvinto a large number of sections.
The principles of the present invention are best illustrated by means of a scanning beam of electrons generated by a conventional scanning electron microscope, wherein a narrow beam of electrons impinges on the surface under investigation and as a result electrons emanate therefrom in substantially straight lines.
Basically, the present invention provides means providing an impinging beam of electrons on a surface, the topography of which is to be determined, detection means for detecting electrons emanating from the surface in response to said impinging beam, means providing relative motion between said impinging beam and the surface such that said impinging beam impinges upon various points on the surface producing at each point electrons emanating therefrom and shield means for preventing said emanating electrons from a portion of the points on the surface from reaching said detection means, whereby the output of said detection means is a function of the elevation of said portion of points.
BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of the present invention reference should now be had to the following detailed description thereof taken in conjunction with the accompanying drawings wherein:
FIG. 1 is a schematic representation of the apparatus according to the present invention;
FIG. 2 is an enlarged pictorial fragmentary view of a portion of the apparatus illustrated in FIG. 1;
FIG. 3 is a sectionalview taken along line 3-3 of FIG. 2;
FIG. 4 is a view similar to FIG. 3 illustrating a different angular arrangement of the elements.
DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings and particularly to FIGS. 1 and 2, a housing 10 defines an evacuated chamber 12 through which projects the electronoptical column 14 of a conventional scanning electron microscope, the deflection apparatus of which causes a narrow beam of electrons 16 to scan a specimen 18 under investigation. The specimen I8 is supported on a suitable platform or stage 20 which can be moved, among other desired degrees of freedom, linearly in the direction of arrow A bya suitable actuator such as motor 22.
A detector 24 is responsive to the electron beam 26 emitted or emanating fromthe specimen 18 in response to the impinging beam 16 which sweeps lines in the direction of arrow A and indexes in the direction of arrow B. Alternatively lines can be swept in the direction of arrow B. It is significant that only those electrons emitted from specimen 18 which travel linearly or in straight lines be detected. To this end, detector 24 preferably comprises a backscattered electron collec- I tor or an unbiased secondary emission collector. Moreover the electron sensitive area of this detector should be as small as possible and preferably approaching a point.
Located between the specimen l8 and the detector 24 is a shield means 28 suitably adjustably supported by housing 10 and adjustably movable with respect to specimen 18, said shield means terminating in an edge 30 at the operative end thereof.
As is conventional, the electron-optical column is under the control of a scan generator 32 which synchronizes the motion of the electron beam with a display and/or recorder 34 which responds to a suitably amplified signal from detector 24 via line 36. The display can comprise a cathode ray tube as is well known.
As is best illustrated in FIG. 2 the surface of specimen 18 may have an irregular cross-sectional contour or profile of peaks and valleys which contour may be different in different plane's. For simplicity and ease in presentation the profile is illustrated as grooves having equal peaks and valleys, the difference in elevations of which, the apparatus of the present invention functions to efficiently and accurately detect. The electron sensitive area of detector 24 is depicted by point D. A plane L containing this point and edge 30 makes a known angle with the plane M forming the surface of platform 20. Plane L intersects the specimen surface in a plurality of points P P ,'P P,,, the elevations of whichare to be determined with respect to a datum plane M or, equivalently, with respect to a plane parallel thereto and containing edge 30.
As will be evident from FIG. 3, a line in the plane L originating in a point P in the specimen surface and terminating at the detector D is intersected by the edge 30 at a point R. The distance from point P to point R is a function of the elevation X of the point P relative to the plane which contains edge 30 and is parallel to the plane said distance fixing a distance S measured in the direction of the arrow A. Electrons emanating in straight lines from areas of the specimen surface containing points such'as P to the right of point P as viewed in FIG. 3 and below plane L will be blocked from reaching the sensitivearea D of the detector and, therefore, will be incapable of generating an output signal therefrom to display 34. However, electrons emanating from areas of the specimen surface points such as P" to the left of point P and above plane L will reach the sensitive area D and will generate signals for display 34. Thus, as the electron beam scans the specimen surfacein the direction of arrow A and indexes thereacross in the direction of arrow B causing electrons to be emitted therefrom in straight lines, detectable signals will be generated from detector 24 from all portions of the specimen except for those in the area containinglpoints P. In this manner the boundary of such areas and the location of points P P P P can be recorded and displayed as those which cause the output of the detector to abruptly change in value or magnitude. With a record of the location of these points the elevations thereof can be easily calculated by means of the following relationship:
X S tan 6 where: Xis.the elevation of a point P on the surface, as measured from. the plane which contains edge 30 and is parallel-to plane M. i S is-the distance in the direction of arrow A from pointR to a planecontaining edge 30 and perpendicular to plane M.
6 isas defined hereinabove. These calculations ..can be automatically accomplished by means of suitable analog or digital computers, as iswell known..
To establish the profiles or elevations in different regions of the surface 18, electrons emitted from different areas thereof must be blocked from reaching the "detector24. To this end, the surface can be moved or indexed relative to the edge 30 and the detector 18 permitting'the .determination of the boundaries of additional surfaces areas. This can be repeated as desired to determine the complete topography or elevations of all points on the surface.
Although the-support 20 and shield means 28 have been depicted in parallel planes substantially perpendicular to the axis of the electronoptical column wherein 0 is an acute angle less than 90 other angular arrangements are contemplated. In fact, it has been determined that a preferred orientation would be where 0 equals 90. To this end, the support and shield means could be suitably rotated with respect to the axis of the electron optical column, as depicted schematically in FIG. 4. In this case the elevation X is given by:
X S/sin B 5 where:
B is the angle between the axis of the electron optical column and the plane containing the shield means edge and the sensitive area of the detector.
While preferred embodiments of the present invention have been described, changes will obviously occur to those skilled in the art. For example, although shield means 28 has been disclosed as a planar element having a fine edge other forms are contemplated such as a positive field which blocks electrons from impinging on the detector by the capture thereof. This field, however, must not influence electrons which are in the sight of the detector.
It is therefore intended that the present invention be limited only by the scope of the appended claims.
We claim:
1. A method of enabling the determination of surface elevation, comprising the steps of:
a. projecting a beam of electrons on a surface causing electrons to be emitted therefrom,
b. detecting by means of a detector electrons emitted from the surface,
c. blocking from being detected by blocking means electrons emitted from a first area of the surface, the relative positions of the detector and the blocking means being predetermined, and
d. locating the boundary of said first area by detecting the location of points on the surface at which the output of the detector abruptly changes in value whereby the relative elevations of said points can be determined.
2. The method according to claim 1, further comprising the steps of:
e. blocking from being detected electrons emitted from a second area of the surface, and
f. locating the boundary of the second area by detecting the location of points on the surface at which the output of the detector abruptly changes in value.
3. The method according to claim 2, further comprising the steps of:
g. blocking from being detected electrons emitted from a plurality of additional areas on the surface, and
h. repetitively locating the boundaries of said additional areas by repetitively detecting the location of points on the surface for each additional area at which the output of the detector abruptly changes in value.
4. The method according to claim 3 wherein said step of blocking additional areas is accomplished by moving the surface.
5. The method according to claim 3 wherein said beam of electrons is caused to scan the surface.
6. The method according to claim 5 further comprising the step of:
i. recording the output of the detector.
7. The method according to claim 5 further comprising the steps of:
i. displaying the output of the detector on a display device, and
j. synchronizing the display device with the scanning electron beam.
8. Apparatus for enabling the determination of surface elevation with respect to a datum plane, comprismg: i
a. means for projecting a beam of electrons on a surface causing electrons to be emitted therefrom,
b. detection means for detecting electrons emitted from the surface,
c. means for blocking electrons emitted from a first area of the surface from being detected by said detection means, the relative positions of said detection means and said means for blocking being predetermined, and
d. means for locating the boundary of said first area by detecting the location of points on the surface at which the output of said detection means abruptly changes in value whereby the relative elevations of said points can be determined.
9. The apparatus according to claim 8, wherein said blocking means comprises a shield spaced from the surface and located between the surface and said detection means.
10. The apparatus according to claim 9, wherein said shield has an edge and the boundary of the first area is a line which is defined by the intersection of the surface by a plane containing said edge and said detection means.
11. The apparatus according to claim 10, wherein said plane makes a predetermined angle with respect to the datum plane.
12. The apparatus according to claim 11, further comprising:
e. means for blocking electrons from additional areas of the surface from being detected by said detection means.
13. The apparatus according to claim 12, wherein said last mentioned means comprises means for moving the surface with respect to said blocking means.
14. The apparatus according to claim 12, wherein said means for projecting a beam of electrons includes means for causing said beam to scan the surface.
15. The apparatus according to claim 14, further comprising:
f. a display device for displaying the output of said detection means. and
g. means for synchronizing the display device with said scanning electron beam.
16. The apparatus according to claim 11 wherein said angle is substantially ninety degrees.
17. The apparatus according to claim 8, further comprising:
e. means for recording the output of said detection means.
18. The apparatus according to claim 8, wherein said means for projecting a beam of electrons includes means for causing said beam to scan the surface.
19. The apparatus according to claim 18, further comprising:
e. means for recording the output of said detection means.
20. The apparatus according to claim 18 further comprising:
e. a display device for displaying the output of said detection means, and
f. means for synchronizing the display device with said scanning electron beam.
21. The apparatus according to claim 8, wherein said blocking means is spaced from the surface and located between the surface and said detection means.
22. The apparatus according to claim 21, further comprising:
e. an extremity of said blocking means,
f. an electron sensitive portion of said detection means having an area approaching that of a point, and wherein the boundary of the first area is a line on the surface which is defined by the intersection of the surface by a plane containing said extremity and said electron sensitive portion.
23. The apparatus according to claim 22, further comprising:
g. means for blocking electrons from additional areas of the surface from falling on said electron sensitive portion.
24. The apparatus according to claim 23, wherein said last mentioned means comprises means for moving the surface with respect to said blocking means.
25. The apparatus according to claim 8, wherein said detection means comprises a backscatter detector.
26. The apparatus according to claim 8, wherein said detector means comprises an unbiased secondary emission detector.

Claims (26)

1. A method of enabling the determination of surface elevation, comprising the steps of: a. projecting a beam of electrons on a surface causing electrons to be emitted therefrom, b. detecting by means of a detector electrons emitted from the surface, c. blocking from being detected by blocking means electrons emitted from a first area of the surface, the relative positions of the detector and the blocking means being predetermined, and d. locating the boundary of said first area by detecting the location of points on the surface at which the output of the detector abruptly changes in value whereby the relative elevations of said points can be determined.
2. The method according to claim 1, further comprising the steps of: e. blocking from being detected electrons emitted from a second area of the surface, and f. locating the boundary of the second area by detecting the location of points on the surface at which the output of the detector abruptly changes in value.
3. The method according to claim 2, further comprising the steps of: g. blocking from being detected electrons emitted from a plurality of additional areas on the surface, and h. repetitively locating the boundaries of said additional areas by repetitively detecting the location of points on the surface for each additional area at which the output of the detector abruptly changes in value.
4. The method according to claim 3 wherein said step of blocking additional areas is accomplished by moving the surface.
5. The method according to claim 3 wherein said beam of electrons is caused to scan the surface.
6. The method according to claim 5 further comprising the step of: i. recording the output of the detector.
7. The method according to claim 5 further comprising the steps of: i. displaying the output of the detector on a display device, and j. synchronizing the display device with the scanning electron beam.
8. Apparatus for enabling the determination of surface elevation with respect to a datum plane, comprising: a. means for projecting a beam of electrons on a surface causing electrons to be emitted therefrom, b. detection means for detecting electrons emitted from the surface, c. means for blocking electrons emitted from a first area of the surface from being detected by said detection means, the relative positions of said detection means and said means for blocking being predetermined, and d. means for locating the boundary of said first area by detecting the location of points on the surface at which the output of said detection means abruptly changes in value whereby the relative elevations of said points can be determined.
9. The apparatus according to claim 8, wherein said blocking means comprises a shield spaced from the surface and located between the surface and said detection means.
10. The apparatus according to claim 9, wherein said shield has an edge and the boundary of the first area is a line which is defined by the intersection of the surface by a plane containing said edge and said detection means.
11. The apparatus according to claim 10, wherein said plane makes a predetermined angle with respect to the datum plane.
12. The apparatus according to claim 11, further comprising: e. means for blocking electrons from additional areas of the surface from being detected by said detection means.
13. The apparatus according to claim 12, wherein said last mentioned means comprises means for moving the surface with respect to said blocking means.
14. The apparatus according to claim 12, wherein said means for projecting a beam of electrons includes means for causing said beam to scan the surface.
15. The apparatus according to claim 14, further comprising: f. a display device for displaying the output of said detection means, and g. means for synchronizing the display device with said scanning electron beam.
16. The apparatus according to claim 11 wherein said angle is substantially ninety degrees.
17. The apparatus according to claim 8, further comprising: e. means for recording the output of said detection means.
18. The apparatus according to claim 8, wherein said means for projecting a beam of electrons includes means for causing said beam to scan the surface.
19. The apparatus according to claim 18, further comprising: e. means for recording the output of said detection means.
20. The apparatus according to claim 18 further comprising: e. a display device for displaying the output of said detection means, and f. means for synchronizing the display device with said scanning electron beam.
21. The apparatus according to claim 8, wherein said blocking means is spaced from the surface and located between the surface and said detection means.
22. The apparatus according to claim 21, further comprising: e. an extremity of said blocking means, f. an electron sensitive portion of said detection means having an area approaching that of a point, and wherein the boundary of the first area is a line on the surface which is defined by the intersection of the surface by a plane containing said extremity and said electron sensitive portion.
23. The apparatus according to claim 22, further comprising: g. means for blocking electrons from additional areas of the surface from falling on said electron sensitive portion.
24. The apparatus according to claim 23, wherein said last mentioned means comprises means for moving the surface with respect to said blocking means.
25. The apparatus according to claim 8, wherein said detection means comprises a backscatter detector.
26. The apparatus according to claim 8, wherein said detector means comprises an unbiased secondary emission detector.
US414568A 1973-11-09 1973-11-09 Method and apparatus for determining surface characteristics incorporating a scanning electron microscope Expired - Lifetime US3876879A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
US414568A US3876879A (en) 1973-11-09 1973-11-09 Method and apparatus for determining surface characteristics incorporating a scanning electron microscope
NL7414104A NL7414104A (en) 1973-11-09 1974-10-29 METHOD AND DEVICE FOR DETERMINING SURFACE ELEVATIONS.
GB47837/74A GB1485449A (en) 1973-11-09 1974-11-05 Method and apparatus for examining surface characteristics employing a scanning electron beam
DE2452826A DE2452826B2 (en) 1973-11-09 1974-11-07 Method and device for determining the elevation of points on a surface
JP12948074A JPS5511204B2 (en) 1973-11-09 1974-11-08
FR7437083A FR2250977A1 (en) 1973-11-09 1974-11-08

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DE2635356A1 (en) * 1975-09-24 1977-04-07 Jenoptik Jena Gmbh SCANNING ELECTRON MICROSCOPE FOR CONTROL OF OBJECT STRUCTURES
US4142145A (en) * 1977-12-22 1979-02-27 The United States Of America As Represented By The Secretary Of The Navy Method for determining conduction-band edge and electron affinity in semiconductors
US4144488A (en) * 1977-12-22 1979-03-13 The United States Of America As Represented By The Secretary Of The Navy Investigation of near-surface electronic properties in semiconductors by electron beam scanning
US4475037A (en) * 1982-05-11 1984-10-02 International Business Machines Corporation Method of inspecting a mask using an electron beam vector scan system
US4733075A (en) * 1983-10-20 1988-03-22 Kabushiki Kaisha Toshiba Stroboscopic scanning electron microscope
US4733074A (en) * 1985-04-17 1988-03-22 Hitachi, Ltd. Sample surface structure measuring method
US4788431A (en) * 1987-04-10 1988-11-29 The Perkin-Elmer Corporation Specimen distance measuring system
US4958059A (en) * 1988-07-06 1990-09-18 Commissariat A L'energie Atomique Electronic bombardment evaporator equipped with means to recover backscattered electrons
US5150392A (en) * 1991-09-09 1992-09-22 International Business Machines Corporation X-ray mask containing a cantilevered tip for gap control and alignment
US5734164A (en) * 1996-11-26 1998-03-31 Amray, Inc. Charged particle apparatus having a canted column
US20050205777A1 (en) * 2004-03-22 2005-09-22 Dmitriy Yeremin Method of evaluating of a scanning electron microscope for precise measurements
US20050224457A1 (en) * 2004-03-30 2005-10-13 Tohru Satake Method and apparatus for repairing shape, and method for manufacturing semiconductor device using those
US20080073526A1 (en) * 2006-02-24 2008-03-27 Atsushi Takane Charged particle beam apparatus

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CA1202508A (en) * 1981-05-07 1986-04-01 Norio Murata Protective packaging assembly and method for optical fibers
DE3306194A1 (en) * 1982-02-25 1983-09-08 Mitsubishi Denki K.K., Tokyo METHOD FOR TESTING SCREW SURFACES FOR FAULTS AND DEVICE FOR IMPLEMENTING THEM
JPH0663758B2 (en) * 1987-10-14 1994-08-22 株式会社東芝 Pattern measurement method
DE3811673A1 (en) * 1988-04-07 1989-10-19 Herbert Dr Konitz Scanning electron microscope method for measuring the profiling, in particular the roughness, of surfaces, and device for carrying out the method

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US3549999A (en) * 1968-06-05 1970-12-22 Gen Electric Method and apparatus for testing circuits by measuring secondary emission electrons generated by electron beam bombardment of the pulsed circuit
US3597607A (en) * 1967-02-16 1971-08-03 Cambridge Instr Co Electron probe employing three secondary emission detectors whose outputs are combined to minimize error

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US3549999A (en) * 1968-06-05 1970-12-22 Gen Electric Method and apparatus for testing circuits by measuring secondary emission electrons generated by electron beam bombardment of the pulsed circuit

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2635356A1 (en) * 1975-09-24 1977-04-07 Jenoptik Jena Gmbh SCANNING ELECTRON MICROSCOPE FOR CONTROL OF OBJECT STRUCTURES
US4142145A (en) * 1977-12-22 1979-02-27 The United States Of America As Represented By The Secretary Of The Navy Method for determining conduction-band edge and electron affinity in semiconductors
US4144488A (en) * 1977-12-22 1979-03-13 The United States Of America As Represented By The Secretary Of The Navy Investigation of near-surface electronic properties in semiconductors by electron beam scanning
US4475037A (en) * 1982-05-11 1984-10-02 International Business Machines Corporation Method of inspecting a mask using an electron beam vector scan system
US4733075A (en) * 1983-10-20 1988-03-22 Kabushiki Kaisha Toshiba Stroboscopic scanning electron microscope
US4733074A (en) * 1985-04-17 1988-03-22 Hitachi, Ltd. Sample surface structure measuring method
US4788431A (en) * 1987-04-10 1988-11-29 The Perkin-Elmer Corporation Specimen distance measuring system
US4958059A (en) * 1988-07-06 1990-09-18 Commissariat A L'energie Atomique Electronic bombardment evaporator equipped with means to recover backscattered electrons
US5150392A (en) * 1991-09-09 1992-09-22 International Business Machines Corporation X-ray mask containing a cantilevered tip for gap control and alignment
US5734164A (en) * 1996-11-26 1998-03-31 Amray, Inc. Charged particle apparatus having a canted column
US20050205777A1 (en) * 2004-03-22 2005-09-22 Dmitriy Yeremin Method of evaluating of a scanning electron microscope for precise measurements
US6969852B2 (en) * 2004-03-22 2005-11-29 General Phoshonix Llc Method of evaluating of a scanning electron microscope for precise measurements
US20050224457A1 (en) * 2004-03-30 2005-10-13 Tohru Satake Method and apparatus for repairing shape, and method for manufacturing semiconductor device using those
US7220604B2 (en) * 2004-03-30 2007-05-22 Ebara Corporation Method and apparatus for repairing shape, and method for manufacturing semiconductor device using those
US20070192057A1 (en) * 2004-03-30 2007-08-16 Ebara Corporation Method and apparatus for repairing shape, and method for manufacturing semiconductor device using those
US20080073526A1 (en) * 2006-02-24 2008-03-27 Atsushi Takane Charged particle beam apparatus
US7652249B2 (en) * 2006-02-24 2010-01-26 Hitachi High-Technologies Corporation Charged particle beam apparatus
US8263935B2 (en) 2006-02-24 2012-09-11 Hitachi High-Technologies Corporation Charged particle beam apparatus

Also Published As

Publication number Publication date
DE2452826B2 (en) 1979-10-04
JPS5081175A (en) 1975-07-01
JPS5511204B2 (en) 1980-03-24
GB1485449A (en) 1977-09-14
NL7414104A (en) 1975-05-13
FR2250977A1 (en) 1975-06-06
DE2452826A1 (en) 1975-05-15

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